Slate is one of the finest roofing materials because, among other things, it is fireproof, resists hail damage, and can have a service life of 100 years or more. While natural slate has been common for decades, resent years have seen the immergence of man-made slate roofing that can rival the look and durability of natural slate. Slate roofing also is considered an architectural match for certain home styles.
Slate roofing can be installed in a variety of ways. Traditionally, slate shingles were installed on roof decks with nails driven through holes in the shingles. However, this proved to present certain problems related, among other things, to the weight of the shingles and the consequent enhanced framing required, as well as other factors, which often caused cracking of the brittle slate material. More recently, an improved slate roof installation system has been developed by Elk Premium Building Products, Inc. (now GAF) and is marketed under the trademark TruSlate™. Generally speaking, the TruSlate™ roofing system involves the installation of underlayment and spaced apart metal battens extending horizontally along a roof deck. Spring tempered hangers are attached to the battens and extend down the roof deck to upwardly hooked ends. A waterproof membrane or liner is laid along a row of hangers and individual slate shingles are hung on the hangers in overlapping rows or courses along the roof deck. The result is a classic and stately slate roof that does not exhibit problems caused by stress and roof deck movement. U.S. Pat. Nos. 7,448,177 and 7,454,873 disclose the TruSlate™ roofing system in detail and the entire contents of these patents is hereby incorporated by reference.
Solar electrical energy also is becoming more common as energy prices rise and cultural trends toward greener ways of life are more prevalent. One way of supplementing electrical needs with solar energy is to mount arrays of photovoltaic solar panels on one's roof. The panels often are mounted within frames and are electrically coupled together and connected to a home's electrical service and/or to battery banks to provide electrical energy from the sun. While such arrays of solar panels indeed provide supplemental electricity, many consider them unsightly on a roof and therefore would not invest in such a system. This may be particularly true for homeowners with slate or slate-style roofs, which represent a large investment to obtain the architectural appearance of slate.
U.S. Pat. No. 8,215,070 (incorporated herein by reference and owned by the assignee of the present disclosure) discloses a TruSlate™ type roofing system that includes solar panels that tend to blend into the architecture of surrounding field slates of a slate roof. However, even with the system disclosed in said patent, the solar panels when installed may not blend ideally into architecture of the roof. More particularly, the solar panels may not be completely flush with surrounding field slates because sufficient space for junction boxes and wiring must be provided beneath each of the solar panels. U.S. Pat. No. 8,215,070 suggests incorporating some of the wiring into the battens of the system, but junction boxes of individual solar panels and perhaps nano-inverters still must be accommodated in some fashion, which may prevent the solar panels from lying flush with surrounding shingles and thereby forming a low profile installation.
A need exists for a roof-mounted photovoltaic solar energy collection system particularly for slate-style roofs that is straightforward to install, easily updated to higher electrical production levels, and that is more fully building integrated, meaning that it blends into the architecture of the building and is low profile to blend with surrounding field shingles of the roof. It is to the provision of such a system that the present invention is primarily directed.